Manhattan project

10

Reassemble the Hammerhead Nuclear Missile system

This is a story-related achievement and cannot be missed while playing the Gaea campaign. It will unlock after you recover the two pieces that make up the Hammerhead. Note that at this point you are told to attack Fulcrum, but the time limit is artificial and to make later gameplay easier I highly recommend capturing all other islands first (likely Lingard and Isolus).